Filtering assembly



.Fuiy 2%, 1965 MULLER FILTERING ASSEMBLY 3 Sheets-Sheet 1 Original FiledNov. 30, 1956 INVENTOR JACQUES MULLER BY 5* WWW ATTORNEYS July 20, 1965.1. MULLER FILTERING ASSEMBLY 3 Sheets-Sheet 2 Original Filed Nov. 30,1956 INVENTOR JACQUES MULLER ATTORNEEE July 20, 1965 J. MULLER 3,

FILTERING ASSEMBLY firiginal Filed Nov. 30, 1956 3 Sheets-Sheet 5INVENTOR .JA CQZ/ES MUL 1.5/2

ATTORNEYS M a W II! .F l IIIII ////Am 4 1 NW. VIIIL. I|IIIII|H= H wa l H6 a w a a n B m R United Sttes ate psi Jacques Muller, La Garennefiolombcs, France, assignor to Eellumit Inter, Sarah, LaGarenne-Colomhes, I France, a corporation of France Continuation ofapplication Ser. No, 625,43d, Nov. 36, 1956. This application June 29,1962, Scr. No. 2%,428 Claims priority, application France, last. 18,956, 796,598, Patent 1,141,129 2 Glairns. (El. 213-483) The presentinvention is a continuation of my copending patent application SerialNo. 625,436, filed November 30, 1956, and now abandoned, and relates toWashers or plates with grooves or furrowed faces adapted to form whensuperposed a pervious packing for filter columns or blocks or siftingdiscs.

Washers or plates of this kind are known which have on their two facesparallel grooves or substantially oriented in a single direction. In thecase of annular washers or plates in the form of square or rectangularframes having a central opening and adapted to form, when superposed,the pervious tubular packing of filter columns, there results inevitablytwo zones diametrically opposite which do not allow any passage ofliquid because the secant grooves connect directly between two points ofthe exterior periphery without leaving any opening at the interiorperiphery of the tubular packing. A large portion of the peripheralsurface of filter columns thus rcrnains unutilized because the filteringcan take place only in the zones where the grooves provide communicationbetween the exterior peripheral surface and the interior peripheralsurface.

Another disadvantage of grooves oriented in the same direction is thatit is necessary to give each washer or plate a determined angularorientation in order that the grooves of the contact surfaces of thewashers or plates will cross each other and not become embedded in eachother. Such embedding would result in obstruction of the grooves andwould destroy the filtering properties of the packing.

The object of the present invention is to overcome the above-pointed outdisadvantages.

According to the invention the grooves formed in any suitable materialin the two faces of the annular washers or rectangular frames extendwith the same inclination in the same direction from the interior edgetowards the exterior edge, or vice versa, which gives the assembly ofgrooves of each face an arrangement to some extent radial.

For the annular washers in particular, one feature of the inventionconsists in that the axes of all the grooves incline in the samedirection, are tangent to a circle prefe ably internal, and concentricwith the axis of the washer.

Another feature consists in that the width or depth of the grooves, orin other words the cross section of the grooves, increases progressivelyin the direction of flow of the fluid to be filtered, that is to say,from the interior periphery towards the exterior periphery of the washerwhen the filtering takes place from the interior to the exterior of thecolumn, or in the opposite direction when the filtering takes place fromthe exterior towards the interior.

Due to the orientation to some extent tangential of all the groovesinclined in the same direction with respect to the two peripheral edgesof each face of the annular washers, the total peripheral interior andexterior surfaces of the column of filtering packing formed by a stackof these washers, is utilised for filtering because these surfaces donot have any dead zones since each point of the exterior circumferenceis connected to a corresponding point of the interior circumference forthe passage of fluid.

stasis The arrangement of the groovesis'identical onleach face of awasher viewed in plan so that the grooves of two faces are crossed,which is also the case for the grooves of the surface of contact of twosuperposed washers. This crossing of the grooves of the contact surfacesis assured, whatever may be the angular orientation of the washer, sothat there is no need to provide means giving each washer apredetermined orientation depending on the inclination of the grooves.

For greater clearness, the invention will be described hereinafter indetail with reference to the annexed drawings which show severalembodiments thereof.

it these drawings:

FIGURE 1 is a perspective View of an annular washer according to theinvention in which the grooves are formed for filtering from theinterior towards the exterior;

FIGURES 2 and 3 are plan views or" the two faces of the washer of FIGURE1;

FIGURE 4 is a fragmentary detailed plan view on a larger scale of oneface of the washer;

FIGURE 5 is a fragmentary detailed elevational view of the outer edge ofwasher taken in the direction of the arrow A in FIGURE 4;

FIGURE 6 is a fragmentary detailed elevational view of the inner edge ofthe washer taken in the direction of the arrow B in FIGURE 4;

FEGURE 7 is a fragmentary detailed plan view on a larger scale of oneface of a washer having curved grooves;

FlGURE 8 is a perspective view of an annular washer according to theinvention in which the grooves are formed for filtering from theexterior towards the interior;

FIGURES 9 and 10 areplan views of the two faces of the washer of FIGURE8;

FIGURE 11 is a fragmentary detailed plan view on a larger scale of oneface of the washer of PlGURE 8;

FEGURE 12 is a fragmentary detailed elevational view of the outer edgeof the washer of FIGURE 8 taken in the direction of the arrow C inFIGURE 11;

FIGURE 13 is a fragmentary detailed elevational view of the inner edgeof the washer of FIGURE 8 taken in the direction of the arrow D inFIGURE 11;

FIGURE 14 is a view in axial section through a filter column in whichthe pervious packing is formed by washers according to the invention;and

FIGURE 15 is an axial section of a column of pervious packing formed bywashers according to the invention, but adapted for the separation or"liquids of dilferent densities.

In the example shown in FIGURE 1 it will be seen that the annular washer1 has on its two faces grooves 2 of triangular section and rectilinearaxis. They have any desired dimensions which may be even microscopicwith a width and a depth amounting to at least one micron for filteringfluid containing a suspension of extremely fine particles.

FIGURES 2 and 3 show that the two faces of the washers are identical. Itwill be noted particularly that the grooves 2 formed in these two facesextend with the same inclination in the same direction from the interioredge towards the exterior edge and vice versa, which gives to each facean aspect of lines to some extent radial.

This identical inclination and in the same direction of the grooves maybe obtained by the fact that the am's 3 of all the grooves 2 are tangentto an imaginary circle 4 concentric with the peripheral edges of thewasher. The degree of inclination of the grooves is thus determined bythe diameter of the imaginary circle. It is possible, of course, todetermine the inclination in any other manner.

The two faces being identical, it is obvious that their grooves crosseach other, which signifies that the grooves tails of either face of thewasher.

of the upper face of a washer are crosswise to the grooves of the lowerface of a superposed washer.

For this washer intended for filtering from the interior toward theexterior, the desired feature of the invention results automaticallyfrom the axes of the grooves being tangential to the imaginary circle 4whereby these radiating axes and the sides of the grooves are spacedapart progressively from each other towards the exterior which gives thegrooves a Width and a cross section which progressively increases. Incomplementary fashion the depth can also be progressively increased asclearly shown in FIGURE 1. This increase of the cross section in thedirection of flow of the fluid to be filtered gives an importantadvantage in that the solid particles which have penetrated into thechannels formed by the superposition of a plurality of washers cannotbecome wedged in these channels, which avoids their obstruction. It istherefore less often necessary to disassemble the washers for washingsince the clearing of the inlet openings of the channels over all theinterior periphery of the washers can take place without disassemblingthe pervious packing.

FIGURE 4 shows in plan and on a larger scale the de- The arrangement andthe profile of the grooves are clearly shown.

FIGURES 5 and 6 show' respectively the different profiles of the groovesover the exterior periphery and over the interior periphery of eachwasher.

Obviously it is not indispensable to give the axes of the grooves arectilinear form, as in the example of FIG- URES 1.to 6. For example,these axes can be incurved in a manner shown in FIGURE 7 which may be ofadvantage in certain applications of filter columns with washers soconstructed.

The explanations given above apply equally to the embodiment of theannular washer shown in FIGURES 8 to 13 except that the grooves 2 areprofiled for filtering from the exterior towards the interior, that isto say, that their section increases progressively from the exteriortowards the interior of each washer. The width of the section of thegrooves at the interior periphery of each washer is then determinedessentially by the spacing of their axes, whereby the smallest sectionon the exterior periphery. can be arbitrarily chosen. i This resultsinevitably in residual faces which can, however, be reduced to a minimumand which serve in any manner as support surfaces.

FIGURE 14 shows a filter column utilising grooved washers according tothe invention for the formation of the pervious packing.

This filter column comprises an annular base 10, the lower face of whichis provided with the concentric cylin-. drical collar-like projection 11threaded exteriorly and adapted to be screwed into a correspondingorifice formed in the separating partition (not shown), between theinlet chamber and the outlet chamber of filtering apparatus, the sealingbeing assured by a washer 12. In this base is axially embedded in anysuitable manner one end of a perforated tube 13 which is provided withslotted emvention. The packing may be compressed to any desired extentby screwing or unscrewing the rod 16 in the nut 22 which increases orreduces the tension of the spring 21 and the pressure exerted by the cap14 on the stack of washers.

The spring 21 interposed between the head 18 of the rod 16 and thebottom of the cap 14 serves the function of compensating the expansionduring the operation of the filter column for maintaining a pressure asconstant as possible on the washers forming the pervious packing 23.This column can serve for filtering from the interior to the exteriorwith Washers of the type shown in FIG- URE 1, or for filtering from theexteriortoward the interior with washers of the type shown in FIGURE 8.

FIGURE shows another embodiment of a column with pervious packing formedby Washers according to the invention used not for filtration but forseparation of two liquids of different densities. It is known that theforced flow of an emulsion through a porous mass rebossed portions oropenings of other form from end to end. The other end of this tube iscovered by a cap 14. In the upper face of this cap there is provided acylindrical recess 15 centered on the axis of the tube 13, and in thebottom of which is a central hole for the passage of a smooth rod 16. Apart 17 of the rod near its lower end is screw-threaded while the upperend is provided with an actuating head 13. In the bottom of the recess15 is located a sealing gasket 19 on which rests the pressing washer 20.Between this washer and the head 18 0f the rod is interposed acompression and compensating spring 21. The threaded portion 17 of therod is engaged in a nut 22 fixed to the interior of the tube'13 andconcentric therewith. Thistube' 13 carries exteriorly betweenthe base 10and the cap 14 a filter packing 23 formed of annular washers accordingto the present insults in breaking of the emulsion and that the forcedflow of a mixture of liquids of different densities results in theseparation of these liquids. Now it has been found that the same resultis obtained by forcing an'emulsion or a mixture of liquids through themicroscopic channels of a pervious packing formed by washers accordingto the invention.

The column illustrated comprises the hollow base 39 in the form of a cupwhich is fixed by means of a flange in an opening formed in thepartition 31 which separates the inlet chamber from the decantationchamber 33 of the separator. In the cuplike base 39 is an embeddedperforated tube 34 which is provided with perforated or slottedembossing or other openings from one end to the other and which has itsfree end covered by a cap 35. In the bottom of this cap is screwed acentral rod 36 which can pass freely through a central hole in thebottom of the base St). The lower end of this rod is screwthreaded andcarries a nut 37. Between this nutrand the bottom of the base 3t) isinterposeda compression spring 38. In the lower part of the base 38 areformed orifices 39 for the flow of the emulsion or mixture. The upperedge of the base St) has a peripheral fiange surrounding the tube 34 andadapted to provide a seat for the pervious packing 46 formed by theannular washers according to the present invention stacked about thetube. This packing is thus interposed between the base 39 and the cap,and it may be more or less tightened by screwing or unscrewing the nut37, the spring 33 acting as a compensating means for expansion as in thepreceding example, as shown in FIGURE 14. Between the cap 35 and theuppermost washer of the packing 4.6 there is clamped the bottom of aprecipitation bell 41, the peripheral wall of which is perforated,slotted, or rendered permeable in any other manner from one end to theother. 7 V The mixture of two liquids of different densities, forexample, enters through the bottom of the base 3%) into the tube 34,flows from the interior toward the exterior through the microscopicchannels provided by the stacked washer-s 40, and the bell 41 receivesthe two separated liquids. It allows the lighter liquid to escapethrough its perforations and to rise, but it obliges the heavier liquidto descend and collect on the partition 31 from which it can ;bedischarged. FIGURE 15 shows a vertical arrangement but, if desired, thearrangement may be horizontal.

It is understoodthat the invention is not limited to the examplesdescribed and shown in the drawings since other embodiments andmodifications can be made without departing from the principle of theinvention.

I claim:

1. A filtering assembly comprising a plurality of thin filtering platesdisposed in superimposed relationship to define a tubular filteringcolumn through which a liquid to be filtered flows from one peripherythereof to the other, each filtering plate being annular and providedWith a plurality of microscopic grooves in both surfaces thereof, saidgrooves being contiguous to each other, each groove extending betweenthe inner and outer peripheral edges of the plate, each groove having atriangular cross section which has a predetermined size to keep minuteforeign particles of at least said predetermined size from entering thegroove, each groove progressively increasing in depth and width in thedirection of filtration of the liquid so that minute particles less thansaid predetermined size will pass freely through the groove duringfiltration without becoming wedged therein, the length- Wise axes of allthe grooves in each surface being inclined in the same general directionand being tangent to an imaginary circle on the interior of the platewhich is concentric with the axis of the annular plate; said grooves inhaving a similar inclination in each surface of each filter platecontacting the top surfaces of the grooves in an adjacent filter platein crosswise relation- 6 ship thereby utilising a large proportion ofthe peripheral surface of the tubular filtering column.

2. A filtering assembly as claimed in claim 1, in Which the triangularcross section of the grooves is substantially equilateral.

References liter by the Examiner UNITED STATES PATENTS REUBEN FRIEDMAN,Primary Examiner.

HARRY B. THORNTON, HERBERT L. MARTIN,

Examiners.

1. A FILTERING ASSEMBLY COMPRISING A PLURALITY OF THIN FILTERING PLATESDISPOSED IN SUPERIMPOSED RELATIONSHIP TO DEFINE A TUBULAR FILTERINGCOLUMN THROUGH WHICH A LIQUID TO BE FILTERED FLOWS FROM PERIPHERYTHEREOF TO THE OTHER, EACH FILTERING PLATE BEING ANNULAR AND PROVIDEDWITH A PLURALITY OF MISCROSCOPIC GROOVES IN BOTH SURFACES THEREOF, SAIDGROOVES BEING CONTIGUOUS TO EACH OTHER, EACH GROOVE EXTENDING BETWEENTHE INNER AND OUTER PERIPHERAL EDGES OF THE PLATE, EACH GROOVE HAVING ATRIANGULAR CROSS SECTION WHICH HAS A PREDETERMINED SIZE TO KEEP MINUTEFOREIGN PARTICLES OF AT LEAST SAID PREDETERMINED SIZE FROM ENTERING THEGROOVE, EACH GROOVE PROGRESSIVELY INCREASING IN DEPTH AND WIDTH IN THEDIRECTION OF FILTRATION OF THE LIQUID SO THAT MINUTE PARTICLES LESS THANSAID PREDETERMINED SIZE WILL PASS FREELY THROUGH THE GROOVE DURINGFILTRATION WITHOUT BECOMING WEDGES THEREIN, THE LENGTHWISE AXES OF ALLTHE GROOVES IN EACH SURFACE BEING INCLINED IN THE SAME GENERAL DIRECTIONAND BEING TANGENT TO AN IMAGINARY CIRCLE ON THE INTERIOR OF THE PLATEWHICH IS CONCENTRIC WITH THE AXIS OF THE ANNULAR PLATE; SAID GROOVES INHAVING A SIMILAR INCLINATION IN EACH SURFACE OF EACH FILTER PLATECONTACTING THE TOP SURFACES OF THE GROOVES IN AN ADJACENT FILTER PLATEIN CROSSWISE RELATIONSHIP THEREBY UTILISING A LARGE PROPORTION OF THEPERIPHERAL SURFACE OF THE TUBULAR FILTERING COLUMN.